Bug 2542281

Summary: CVE-2026-100888 opendkim: opendkim: Denial of Service via out-of-bounds write in dkim_canon_selecthdrs [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Ganesh <gnaik>
Component: opendkimAssignee: Jonathan Wright <jonathan>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: anon.amish, jonathan
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["f22c237d-d6e0-4c8d-a4f5-cd64a7ff693e"]}
Fixed In Version: Doc Type: ---
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2542252    

Description Ganesh 2026-09-28 02:43:44 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A weakness has been identified in Trusted Domain Project OpenDKIM up to 2.11.0. This affects the function dkim_canon_selecthdrs of the file libopendkim/dkim-canon.c of the component DKIM Signature Header Selection. Executing a manipulation of the argument h can lead to out-of-bounds write. The attack can be executed remotely. The exploit has been made available to the public and could be used for attacks. The vendor was contacted early about this disclosure but did not respond in any way.